Spatially programmed polymorphic crystallization via microenvironment design

Organic semiconductor crystals with long-range order and designable properties are pivotal in optoelectronic devices. Organic crystals bonded by weak intermolecular interactions usually follow non-classical crystallization trajectories, yielding polymorphs with distinctive properties but extremely difficult to control. We present a method for deterministic control of polymorphs, yielding organic microcrystal arrays with distinctive crystal structures and emission spectra. To elucidate the mechanisms of molecular self-assembly, we track the real-time dynamics of molecular nucleation, Ostwald's ripening, and polymorph formation. Based on this method, we extended our regulation strategy to multiple molecules, achieving programmable polymorphic formation with broadly tunable emission spectra (450-705 nm) and anisotropic polarized emission. On a single substrate, we integrated multidimensional polymorphic information including position, wavelength, intensity, and polarization, constructing a high-density optical information storage platform with an information density of 215 bits/cm2, thereby opening potential technological pathways for future optical information storage technologies.